Telephone



(No Model.)

, T. A. WATSON.

, TELEPHONE. No. 348,077,

1 Patented Aug. 24, 18.86.

|-|w Pains. Phmuxm n w. Washington. D. c.

' with a diaphragm by a mechanical device for UNITED STATES "ATENTFries.

THOMAS A. WATSON, OF EVERETT, ASSIGNOR TO THE AMERICAN BELL TELEPHONECOMPANY, OF BOSTON, MASSACHUSETTS.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 348,077, dated August24, 1886.

Application filed June 15, 1880.

To all whom, it may concern Be it known that I, THOMAS A. WATSON, ofEverett, county of Middlesex, State of Massachusetts, have invented anImprovement in Telephones, of which the following description, inconnection'with the accompanying drawing, is a specification.

My invention relates to telephones, and has for its object to increasethe amplitude of the vibrations of the diaphragm Which gives out thesound, or of the armature or vibrating contact electrodes, or otherdevice used to produce a varying electric impulse, thus increasing theloudness and volume of the sound received.

The invention is herein shown embodied in a magnetotelephone; and itconsists in con necting the armature of the magnet thereof increasingrange of movement, herein shown as a simple lever, the connectedarmature and diaphragm taking the place of the usual diaphragm, whichitself forms the armature of and is vibrated by the magnet.

When the instrument is to be used as a transmitter, the armature anddiaphragm should be so connected that the movement of the former isgreater than that of the latter, so that the currents induced will bestronger, and consequently have a more powerful effect upon thereceiving-telephone. In some cases it may be desirable to increase theamplitude of movement of the vibrating point of a microphone orbattery-transmitter.

The drawing shows a plan view of a magneto-telephone embodying myinvention, part being shown in section.

The magnet a is shown as ahorseshoe-magnet, suitably supported, as at b,in proper position to have its poles 0, provided with the usualinduction-coils,d, act on the armature e, of suitable size and form tobe strongly affected thereby. The armature e is rigidly attached to alever, f, having one end pivoted at g and the other end rigidlyconnected with the diaphragm h, which is placed in front of the usualsound-chamber and mouth-piece and may be of any desired material notnecessarily magnetic. By this arrangement it will be seen that anyvibration imparted to thelcver f will be transmitted to the diaphragm,and that] Serial No.11,765. (No model.)

according to the well-known mechanical principle of the lever, themovement of the extremity of the lever connected with the diaphragm willbe greater than that of any intermediate point thereof in the ratio ofthe whole length of the said lever to that of the portion between thesaid intermediate point and the fulcrum g.

When constructed in the proportions shown in the drawing, the amplitudeof movement of the end of the lever fand the connected diaphragm it willbe about three times as great as that of the armature e, and the effectof the vibrations of the said diaphragm h on the air to producesound-waves will be considerably greater and will produce considerablylouder sound than a diaphragm vibrated in the ordinary way by the directmagnetic impulses.

The leverf should be of light stiff material, hard tough wood having acompact grain being found very good for this purpose.

If it is desired to use the telephone as a transmitter, the amplitude ofvibration of the armature 6 should be increased, which may be done byconstructing the telephone with the positions of the diaphragm andmouth-piece and the armature and magnet reversed, the

diaphragm being connected with the lever at some intermediate point, andthe armature secured to the free end thereof; or the parts may remain inthe same position relative to the lever, which should then be pivoted ata point between the armature and diaphragm and nearer the latter, as atm, instead of g. WVhen the same instrument is to be used as atransmitter and receiver, suitable pivots may be provided at g and m,and the lever connected with and vibrated on the one or the other, asdesired. It is obvious that a lever of this description can also be usedin connection with the contactelectrodes of a microphone orbattery-transmitter when it'is desired to have the vibrations of themovable electrode of different amplitude from those of the diaphragm.

I do not limit myself to a lever as the means for increasing the rangeof movement or am plitude of vibration of one of the movable parts setin motion by the other, as other mechanically-equivalent devices fortransmitting and increasing motion may be used.

I claim- 1. In a telephonic instrument, a diaphragm to receive or impartsound-waves, combined with a lever rigidly connected therewith to enablea point on the said lever to have a vibra tory movement of greateramplitude than that of the diaphragm, substantially as described.

2. In a telephone, an armature-lever arranged in contact with thediaphragm and provided with an adjustable fulcrum, substantially asdescribed, whereby on changing the fulcrum the vibrations of thearmature or of the diaphragm may be communicated from either to theother with an augmented or diminished force.

3. The combination of a diaphragm, arma- I5 tore-lever, and magnetadjustable with reference to the armature-lever, substantially asdescribed.

In testimony whereof I have signed my name to this specification in thepresence of two sub- 20 scribing witnesses.

THOMAS A. WATSON.

Witnesses:

J os. P. LIVERMORE, N. E. O. WHITNEY;

